( Concave Rectangle  - Piece )
G21
G91
G99 X1.00 Y0.00 I0 J0
G42
M07
G01 X0.00 Y5.000
G01 X0.00 Y100.000
G02 X-100.000 Y0.00 I-50.000 J0.00
G01 X0.00 Y-100.000
G01 X100.000 Y0.00 
G01 X5.000 Y0.00
M08
G40
M02
